Base for electric-lamp bulbs.



No. 777,741. PATENTED DEC. 20, 1904.

I G P MoDONNELL BASE FOR ELEGTRIG LAMP BULBS.

APPLICATION FILED MAB-12,1904.

N0 MODEL.

/ O/7 VINVENTOR.

BY 1 W44 ATTORNEY.

Patented December 20, 1904.

PATENT OFFICE.

GEORGE P. MoDONNELL, OF ST. LOUIS, MISSOURI.

BASE FOR ELECTRIC-LAMP BULBS.

SPECIFICATION forming part of Letters Patent No. 777,741, dated December20, 1904. Application filed March 12, 1904:. Serial No. 197,808.

To all whom it may concern..-

Be it known that I, GEORGE P. MoDoNNELL, a citizen of the United States,residing at St. Louis, State of Missouri, have invented certain new anduseful Improvements in Bases for Electric-Lamp Bulbs, of whichthe'following is a full, clear, and exact description, reference beinghad to the accompanying drawings, forming a part hereof.

My invention has relation to improvements in bases for electric-lampbulbs; and it consists in the novel construction and arrangement ofparts more fully set forth in the speci fication and pointed out in theclaims.

In the drawings, Figure 1 is an elevation of a bulb having my inventionapplied thereto. Fig. 2 is a middle vertical section on the line 2 2 ofFig. 3. Fig. 3 is a horizontal section on line 3 3 of Fig. 2. Fig. 4 isan' elevation of the plug and conducting-nail carried thereby. Fig. 5 isa perspective view of a modified form of base; and Fig. 6 is a top planof Fig. 5, showing a portion of the bulb to which the base is secured.

The object of my invention is to provide an electric-lamp bulb with abase which can be attached thereto without the use of cement or similaradhesive or without the use of solder, both of which are objectionable,the former on account of the danger of short-circuiting the currentpassing to the lighting-filaments by reason of the moisture absorbed bysuch cement and the latter on account of the increased cost ofmanufacture.

The advantages of my present improvement will be better apparent from adetailed description of the invention, which is as follows:

Referring to the drawings, 1 represents a conventional form ofelectric-lamp bulb having the usual central inwardly-projecting hollowstem 2 for the insertion of the conductingwires w w, whose inner endsare respectively electrically coupled to the lighting-filaments 3, theinner end of the stem being, as is well known, hermetically sealed. Overthe reduced end or neck of the bulb is passed the metallic base 4, whichis ordinarily secured to said neck by means of plaster-of-paris, cement,or other suitable adhesive, the said base being in the form of athreaded or spirallyribbed ring which screws into the socket 5,receiving the electric supply-wires and which carries the switch 6, bywhich the current is turned on or off, all as is well known andunderstood. By my present improvement the cement is dispensed withaltogether, the connection between the base and bulb being effected asfollows: In the preferred form of my invention the upper end of the baseor ring 4 is closed by an insulating disk 7, through a central openingof which is passed a cork plug 8, of a length to partially enter thehollow stem when the base is passed its full length over the neck of thebulb. The cork plug not only serves to separate and permanently keepapart the wires w 20, but it assists in part to frictionally hold thebase to the bulb, said base being further secured to said bulb by theusual label 9, (indicating the voltage and candlepower,) which in thepresent instance is so attached as to overlap the basal lobes 4 of thering 4, the label thus adhering simultaneously to the glass bulb and tothe lobe 4. as clearly seen in Fig. 1. Into the cork plug 8 is drivencentrally a metallic nail 10, around whose pin portion is wound theupper end of thewire w, and when the nail is driven home the headthereof, bearing against the cork, retains the wire permanently inplace. The head of the nail of course is in permanent electric contactwith the base of the socket 5, so that when the switch 6 is turned inthe proper direction to close the circuit the current flows into thefilaments and produces a light. The disk 7 is of course perforated forthe free passage of the wire 20 therethrough to permit the windingthereof about the nail. The adjacent portion of the opposite wire 20 ispreferably folded around the edge and against the outer face of the neckof the bulb, and after the base or ring 4 has been passed over it theend of the wire is folded against the face of the lobe 4' before thelabel 9 is applied. The wire is thus held frictionally againstdisplacement between the bulb and the base, the latter conducting thereturn-current into the socket to the return member of the supply-wires,and the end of the wire thus turned up against the lobe 4 is held inplace by the label spanning the lobe roo and adhering to the bulb. Thebase 4, on the other hand, is held to the bulb by, first, the

frictional connection between the stem 2 and the plug 8, mounted in thedisk 7, forming a part of said base, and, second, by the adhesion of thelabel 9 to the bulb and lobe 4:, respectively. The Wires 1.0 w are keptpermanently apart by the plug, which was forced between them, and sincethe layer of cement usually interposed between the base i and bulb isabsent the danger of the absorption of moisture by this layer and thedanger of shortcircuiting the current and blowing the fuse is entirelyeliminated.

Of course it is obvious that only one of the conducting-wires, 111), maycontact with the base or ring 4 and that the other wire, 10, must beeither insulated therefrom or otherwise kept permanently out of contacttherewith, (to avoid short-circuiting.)

In my preferred form of construction I employ the insulating-disk 7though in the modification shown in Figs. 5 and 6 I may even dispensewith this element. In lieu thereof I form the base entirely of metal,including the closed top through which the plug is passed. I excise fromsaid closed top a segmont S, so as to leave a clear space around thewire w coupled to the nail 10, said space serving the purpose of aninsulating medium and preventing contact between the wire 20 and themetal portion of the modified base 4". The wall of the socket 11 of saidbase 4", through which the plug 8 is inserted, is longitudinallyroughened or corrugated, so as to better grip the 'plug and insure arigid frictional connection between the parts. The plug, while herereferred to as a cork plug, the preferred material, may of course becomposed of any suitable non-conductor of electricity. So, too, may thedetails of the present construction be altered without in any wiseaffecting the nature or spirit of my invention. For example, what arespecifically herein referred to as lobes A may of course have anycontour or shape so long as they project beyond the adjacent edge of thering A proper.

Other changes will occur to the skilled mechanic which will fall withinthe spirit and contemplation of the present invention.

Having described my invention, what I claim is 1. A base for anelectric-lamp bulb comprising a ring adapted to be passed about the'neck of the bulb, and a plug carried by the ring for entering the hollowstem of the bulb, substantially as set forth.

2. A base for an electric-lamp bulb comprising a ring adapted to bepassed about the neck of the bulb, and an insulating-plugcarried by thering for insertion into the hollow stem of the bulb, substantially asset forth.

3. A base for an electric-lamp bulb comprising a ring adapted to bepassed about the neck of the bulb, an insulating-plug carried by thering for insertion into the hollow stem of the bulb, and a metallic headon the plug adapted to be coupled to the adjacent end of one of theconducting-wires leading to the lighting-filament, substantially as setforth.

4. A base for an electric-lamp bulb comprising a ring adapted to bepassed about the neck of the bulb, a non-conducting plug carried by thering for insertion into the hollow stem of the bulb, and anelectrically-conducting head at the outer end of the plug, substantiallyas set forth.

5; A base for an electric-lamp bulb comprising a ring adapted to bepassed about the neck of the bulb, an insulating-disk closing the outerend of the ring, a non-conducting plug carried by the disk for insertioninto the hollow stem of the bulb, leading-in wires for the current, anail having a head adapted to conduct the current to one of the wiresleading to the lighting-filament, the disk being perforated for the freepassage of said wire and the latter being connected to the nail, theopposite wire being passed and folded over the edge of the neck andfrictionally held between it and the ring, substantially as set forth.

6. A base for an electric-lamp bulb comprising a ring adapted to bepassed about the neck of the bulb, and having one or more lobes at itsinner edge, in combination with a bulb, and an adhesive label passedover and adhering respectively to the bulb and to the lobe,substantially as set forth.

7. A base for an electric-lamp bulb comprising a screw-threaded ringadapted to be passed about the neck of the bulb, and an insulating-plugcarried by the same for insertion into the hollow stem of the bulb,substantially as set forth.

8. A base for an electric-lamp bulb comprising a screw-threaded ringadapted to be passed about the neck of the bulb, an insulating-plugcarried thereby for insertion into the hollow stem of the bulb, and ametallic conducting head or tip on the outer end of the plug,substantially as set forth.

9. A base for an electric-lamp bulb comprising a screw-threaded ringadapted to be passed about the neck of the bulb, an insulating-diskclosing the outer end of the ring, a central plug made of non-conductingmaterial carried by the disk for insertion into the hollow stem of thebulb, the disk being perforated to admit the passage of one of theconducting wires therethrough, and the plug serving to separate theconducting-wires leading from the lighting-filament through the stem,substantially as set forth.

10. The combination with an electric-lamp bulb having a hollow stein,for the reception of the cond ucting-wires leading from thelighting-filainent, of a base passed over the neck of the bulb, means onsaid base for effecting electric connection between one of said wiresand the switch-socket, the opposite wire being folded over the neck andthe end subsequently folded against the base, and a label adhering tothe bulb and passed over the terminal folded end of the Wire and theportion of the base against which the same is folded, substantially asset forth.

In testimony whereof I affix my signature in presence of two witnesses.

GEORGE P. MODONNELL. VVitnesse-s:

EMIL STAREK, MARY D. WHITCOMB.

